328 research outputs found
IN-SYNC. V. Stellar kinematics and dynamics in the Orion A Molecular Cloud
The kinematics and dynamics of young stellar populations enable us to test
theories of star formation. With this aim, we continue our analysis of the
SDSS-III/APOGEE IN-SYNC survey, a high resolution near infrared spectroscopic
survey of young clusters. We focus on the Orion A star-forming region, for
which IN-SYNC obtained spectra of stars. In Paper IV we used these
data to study the young stellar population. Here we study the kinematic
properties through radial velocities (). The young stellar population
remains kinematically associated with the molecular gas, following a
gradient along filament. However, near the center
of the region, the distribution is slightly blueshifted and asymmetric;
we suggest that this population, which is older, is slightly in foreground. We
find evidence for kinematic subclustering, detecting statistically significant
groupings of co-located stars with coherent motions. These are mostly in the
lower-density regions of the cloud, while the ONC radial velocities are
smoothly distributed, consistent with it being an older, more dynamically
evolved cluster. The velocity dispersion varies along the filament.
The ONC appears virialized, or just slightly supervirial, consistent with an
old dynamical age. Here there is also some evidence for on-going expansion,
from a --extinction correlation. In the southern filament, is
-- times larger than virial in the L1641N region, where we infer a
superposition along the line of sight of stellar sub-populations, detached from
the gas. On the contrary, decreases towards L1641S, where the
population is again in agreement with a virial state.Comment: 14 pages, 13 figures, ApJ accepte
Effects of nintedanib on symptoms in patients with progressive pulmonary fibrosis
BACKGROUND: Dyspnoea and cough can have a profound impact on the lives of patients with pulmonary fibrosis. We investigated the effects of nintedanib on the symptoms and impact of pulmonary fibrosis in patients with progressive pulmonary fibrosis (PPF) in the INBUILD trial using the Living with Pulmonary Fibrosis (L-PF) questionnaire. METHODS: Patients had a fibrosing interstitial lung disease (ILD) (other than idiopathic pulmonary fibrosis) of >10% extent on high-resolution computed tomography (HRCT) and met criteria for ILD progression within the prior 24 months. Patients were randomised 1:1 to receive nintedanib or placebo. Changes in L-PF questionnaire scores from baseline to week 52 were assessed using mixed models for repeated measures. RESULTS:In total, 663 patients were treated. Compared with placebo, there were significantly smaller increases (worsenings) in adjusted mean L-PF questionnaire total (0.5 versus 5.1), symptoms (1.3 versus 5.3), dyspnoea (4.3 versus 7.8) and fatigue (0.7 versus 4.0) scores in the nintedanib group at week 52. L-PF questionnaire cough score decreased in the nintedanib group and increased in the placebo group (-1.8 versus 4.3). L-PF questionnaire impacts score decreased slightly in the nintedanib group and increased in the placebo group (-0.2 versus 4.6). Similar findings were observed in patients with a usual interstitial pneumonia-like fibrotic pattern on HRCT and in patients with other fibrotic patterns on HRCT.CONCLUSION: Based on changes in L-PF questionnaire scores, nintedanib reduced worsening of dyspnoea, fatigue and cough and the impacts of ILD over 52 weeks in patients with PPF.</p
Effects of nintedanib on symptoms in patients with progressive pulmonary fibrosis
BACKGROUND: Dyspnoea and cough can have a profound impact on the lives of patients with pulmonary fibrosis. We investigated the effects of nintedanib on the symptoms and impact of pulmonary fibrosis in patients with progressive pulmonary fibrosis (PPF) in the INBUILD trial using the Living with Pulmonary Fibrosis (L-PF) questionnaire. METHODS: Patients had a fibrosing interstitial lung disease (ILD) (other than idiopathic pulmonary fibrosis) of >10% extent on high-resolution computed tomography (HRCT) and met criteria for ILD progression within the prior 24 months. Patients were randomised 1:1 to receive nintedanib or placebo. Changes in L-PF questionnaire scores from baseline to week 52 were assessed using mixed models for repeated measures. RESULTS:In total, 663 patients were treated. Compared with placebo, there were significantly smaller increases (worsenings) in adjusted mean L-PF questionnaire total (0.5 versus 5.1), symptoms (1.3 versus 5.3), dyspnoea (4.3 versus 7.8) and fatigue (0.7 versus 4.0) scores in the nintedanib group at week 52. L-PF questionnaire cough score decreased in the nintedanib group and increased in the placebo group (-1.8 versus 4.3). L-PF questionnaire impacts score decreased slightly in the nintedanib group and increased in the placebo group (-0.2 versus 4.6). Similar findings were observed in patients with a usual interstitial pneumonia-like fibrotic pattern on HRCT and in patients with other fibrotic patterns on HRCT.CONCLUSION: Based on changes in L-PF questionnaire scores, nintedanib reduced worsening of dyspnoea, fatigue and cough and the impacts of ILD over 52 weeks in patients with PPF.</p
Copper (I) SNS Pincer Complexes: Impact of Ligand Design and Solvent Coordination on Conformer Interconversion from Spectroscopic and Computational Studies
The syntheses and detailed characterizations (X-ray crystallography, NMR spectroscopy, cyclic voltammetry, infrared spectroscopy, electrospray mass spectrometry, and elemental analyses) of two new Cu(I) pincer complexes are reported. The pincer ligand coordinates through one nitrogen and two sulfur donor atoms and is based on bis-imidazole or bis-triazole precursors. These tridentate SNS ligands incorporate pyridine and thione-substituted imidazole or triazole functionalities with connecting methylene units that provide flexibility to the ligand backbone and enable high bite-angle binding. Variable temperature 1H NMR analysis of these complexes and of a similar zinc(II) SNS system shows that all are fluxional in solution and permits the determination of ΔGexp‡ and ΔSexp‡. DFT calculations are used to model the fluxionality of these complexes and indicate that a coordinating solvent molecule can promote hemilability of the SNS ligand by lowering the energy barrier involved in the partial rotation of the methylene units
IN-SYNC II: Virial Stars from Sub-Virial Cores -- The Velocity Dispersion of Embedded Pre-Main-Sequence Stars in NGC 1333
The initial velocity dispersion of newborn stars is a major unconstrained
aspect of star formation theory. Using near-infrared spectra obtained with the
APOGEE spectrograph, we show that the velocity dispersion of young (1-2 Myr)
stars in NGC 1333 is 0.92+/-0.12 km/s after correcting for measurement
uncertainties and the effect of binaries. This velocity dispersion is
consistent with the virial velocity of the region and the diffuse gas velocity
dispersion, but significantly larger than the velocity dispersion of the dense,
star-forming cores, which have a sub-virial velocity dispersion of 0.5 km/s.
Since the NGC 1333 cluster is dynamically young and deeply embedded, this
measurement provides a strong constraint on the initial velocity dispersion of
newly-formed stars. We propose that the difference in velocity dispersion
between stars and dense cores may be due to the influence of a 70 micro-Gauss
magnetic field acting on the dense cores, or be the signature of a cluster with
initial sub-structure undergoing global collapse.Comment: Accepted to ApJ. 23 pages, 9 figures and 3 table
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